The US will screen travelers from West African countries hit the hardest by Ebola as part of increased vigilance against an outbreak being called the biggest health threat since AIDS.

The US will screen travelers from West African countries hit the hardest by Ebola as part of increased vigilance against an outbreak being called the biggest health threat since AIDS.

The screening will take place at five international airports — New York’s JFK, Newark in New Jersey, Dulles in DC, O’Hara in Chicago and Hartsfield-Jackson in Atlanta.

Britain said it would also start screening passengers entering the country through London’s two main airports and the Eurostar rail link with Europe.

Screening would involve a temperature check, and questions to travelers about potential exposures and risks. These new measures will “give us the ability to isolate, evaluate and monitor travelers as needed,” said President Barack Obama on Ebola.

The death of a Liberian national in Dallas, Texas, on Wednesday from Ebola was the reason for a new urgency seen in US efforts to combat the disease at home and abroad.

The Ebola outbreak, largest of its kind yet, has affected 8,033 people and killed 3,879, mostly in Sierra Leone, Liberia and Guinea in west Africa.

“I would say that in the 30 years I’ve been working in public health, the only thing like this has been AIDS,” said director of the center for prevention of diseases, Thomas Frieden. But he has also said, “We know how to stop it.”